1. Field of the Invention
This invention relates to a separator. In particular it relates to a separator for separating a relatively small volume e.g. up to 20% of a liquid from a larger volume of another liquid of different density. For example the separator may be used for separating small volumes of oil from produced water from an oil production platform so that the separated water may be returned in a virtually clean condition to the sea. Alternatively the separator, with appropriate adjustments, may be used to separate small quantities of water from crude oil before the oil is subsequently processed.
2. Discussion of Prior Art
It is known to construct a separator for such use in tubular form of reducing circular cross-section from a wide end to a narrow end, having at least one tangentially-disposed inlet at or adjacent the wide end for introducing at relatively high velocity the mixture of liquids to be separated into the separator, and two outlets, the first disposed on the axis of the separator at the wide end for the removal of the less dense liquid component and the second disposed at or adjacent the narrow end for the removal of the more dense liquid component.
During use of such a separator the less dense component, for example oil, moves towards the axis and forms a core and this moves towards the wide end, while the more dense component, e.g. water, moves towards the wall of the separator and towards the narrow end. However it has been found that in some situations not all the less dense component in the central core moves towards the wide end; some of it remains stationary and some even more towards the narrow end where it mixes with and contaminates the more dense component.
It is an object of the present invention to provide a separator in which the above disadvantageous effects are substantially reduced or overcome.